The present invention relates to an improved level adjustment apparatus applicable to apparatus (e.g., audio mixers) including a multiplicity of operators (operating members), such as faders, so as to readily adjust a plurality of kinds of levels in a collective fashion.
Mixer apparatus intended to control various audio equipment in a centralized manner have been employed in various places where concerts, dramatic performance, etc. are given. The mixer apparatus include a multiplicity of operators (operating members), such as faders, so as to adjust various kinds of levels per channel. Particularly, there has been known a type of mixer apparatus which permits grouping of the faders so that tone volume levels of two or more faders can be increased or decreased in a collective fashion, Specifically, in such mixer apparatus, two or more faders are previously defined or set as a fader group so that, when any one of the faders in the group has been operated to increase or decrease the level, the levels of the other faders in the group are automatically increased or decreased in synchronism with the increased or decreased level of the operated fader. Note that each of the faders is a so-called “moving fader” operatively connected to a motor.
The above-mentioned technique of grouping a plurality of faders is very convenient because the user can collectively operate two or more faders whose levels are to be operated in the same level increasing or level decreasing direction. However, there would sometimes arise a need for two faders in a given group to be operated in opposite directions, such as when tone volume crossfade is to be carried out. In such a case, the user of the conventional mixer apparatus has no choice but to simultaneously operate two faders in opposite directions, i.e. level increasing and level decreasing directions, and therefore the user sometimes can not appropriately carry out desired crossfade.